No description available.

No description available.

Introspection has become a significant language feature to enable new component technologies. It enables such capabilities as runtime component discovery, new levels of component flexibility and change tolerance, dynamic reconfiguration and system self healing. Three levels of introspection are discussed: simple type identification, structural introspection, and behavioral introspection The C++ programming language offers type identification, but neither structural or behavioral introspection. Through its use and combination of several language features, C++ has provided a flexible system for achieving some of the features of introspection without explicitly providing it. Features such as templates, operator overloading, polymorphism, and multiple inheritance have allowed software systems in C++ to build flexible components that tolerate change and support dynamic reconfiguration and self healing. The template system in particular has recently been shown to be more capable than expected, being Turing complete in its own right. Despite their existing capabilities, the language features have their limits and would benefit from an introspective mechanism. Unlike traditional introspective systems that execute solely at run-time, Introspective C++ has chosen a compile-time approach that tightly integrates with the template mechanism. This approach enables interaction with the other language mechanisms during the compilation, enabling the resolution of many introspective questions before the compiled program is ever run. Furthermore, the mechanism can serve as a base for developing run-time introspective systems. / Master of Science

[pt] Nos últimos anos, tem crescido a demanda por aplicações hipermídia, as quais relacionam objetos de áudio, vídeo, texto, imagem, etc. no tempo e no espaço. Uma aplicação hipermídia é especificada formalmente em um documento. É comum agrupar um conjunto de aplicações estruturalmente ou semanticamente similares entre si como uma família de documentos. Modelos conceituais para autoria hipermídia são usados como base para a especificação de documentos, mas eles não são satisfatórios para definir famílias de documentos. Este trabalho apresenta um método para a autoria hipermídia baseado na identificação dessas famílias e sua instanciação visando a criação de novos documentos. A principal contribuição deste trabalho é a definição de uma linguagem para a especificação de famílias de documentos, chamada TAL (Template Authoring Language), a qual é empregada no método proposto. TAL se apóia principalmente na extensão do conceito de composição, habitualmente presente em modelos hipermídia. Em TAL, composições podem ser incompletas, com alguns de seus elementos internos propositalmente deixados em aberto e com regras restringindo a forma como esses elementos ausentes podem ser inseridos na composição. Para se chegar a essa linguagem, um estudo empírico foi realizado investigando a aprendizagem e o emprego de Nested Context Language (NCL). A escolha de NCL se deu por ela se basear em um modelo com composicionalidade que pode ser estendido para atender a famílias de documentos, e por ela ser empregada na autoria de documentos hipermídia e passível de ser usada por perfis profissionais diversos e não apenas programadores. Assim, uma terceira contribuição naturalmente decorrente deste trabalho é oferecer diretrizes para a evolução de NCL, em especial aperfeiçoando sua usabilidade. / [en] In the past years, it has increased the demand for hypermedia applications, which relate objects of audio, video, text, images, etc. in time and space. A hypermedia application is formally specified in a document. It is usual to group a set of applications structurally and semantically similar to each other as a documents family. Conceptual models for hypermedia authoring are the basis for documents specification, but they are not satisfactory to define documents families. This work presents as contribution a method for hypermedia authoring based in the identification of these families and their instantiation in order to create new documents. This method addresses the hypermedia document authoring as a social practice, where specialist authors collaborate to help and to ease the task of less skilled authors. Another contribution of this work is to define a language for the specification of these documents families, named TAL (Template Authoring Language), which can be applied in the proposed method. TAL relies mainly on extending the concept of composition, usually present in hypermedia models. In TAL, compositions can be incomplete, with a few of its internal elements purposely left undefined and with restriction rules on how these missing elements may be included in the composition. In order to achieve this language, an empirical study was conducted investigating the learning and use of Nested Context Language (NCL). The choice of NCL relies on the fact that it is based in a compositional model that can be extended to specify documents families, and because it is used by various professional profiles and not just programmers in the hypermedia document authoring. Thus, a third contribution due to this work is to provide guidelines to NCL evolution, especially improving its usability.

No description available.

No description available.

This work describes the research conducted in the quest for designing better software for discrete-event system (DES) control. The think-aloud data from an exploratory observational study of solving DES control problems contributed to the formulation of a list of recommendations on how to design and improve DES software. These observations, together with other relevant research, led to the proposal of a novel approach to DES problem solving, namely, the template design methodology. This methodology does not require the introduction of new control theory; it is rather an reinterpretation of the existing modelling framework. Software supporting this methodology was implemented and subsequently evaluated using twelve subjects. Significant improvements in the speed of problem solving as well as positive evaluations by the subjects were observed. The usability data do not show any drawbacks to applying the methodology. / Thesis (Ph.D, Computing) -- Queen's University, 2009-08-21 17:11:14.991

Thesis (Ph.D.) - University of St Andrews, October 2008. / Restricted until 29th October 2009.

We discuss how to realize simple Smale Flows on 3-manifolds. We focus on three questions: (1) What are the topological conjugate classes of Lorenz Smale flows that can be realized on S3? (2) Which 3-manifolds can also admit a Lorenz Smale flow? (3) What are the topological conjugate classes of simple Smale flows whose saddle set can be modeled by &nu(0+,0+,0,0) can be realized on S3? This dissertation extends the work of M. Sullivan and B. Yu.

In this dissertation, we discuss how to realize simple Smale flows on 3-manifolds. We use four-band and three-band templates to study the linking structure of two types of closed orbits known as attracting closed orbits and repelling closed orbits in the flow. This dissertation extends the work done by M. Sullivan on realizing Lorenz Smale flows on 3-manifolds, by Bin Yu on realizing Lorenz-like Smale flows on 3-manifolds and continues the work of Elizabeth Haynes and Michael Sullivan on realizing simple Smale flows with a four-band template on a 3-sphere. The four-band template we use in this dissertation is different from the template used by Haynes and Sullivan.